The present invention relates to watercraft and, in particular, to enclosures for protecting the hull of a watercraft while moored or stationary in a body of water.
Herein, the term watercraft includes boats, houseboats, barges, scows and other watercraft that are maintained afloat by one or more hulls.
The prior art reveals a variety of enclosures designed to protect the hull of a boat while the boat is moored in a body of water. A primary purpose of such enclosures is to impair the growth of marine organisms on the hulls of boats. When a boat is enclosed, its hull will be shielded from changing marine conditions outside the enclosure. Further, water within the enclosure may be chemically treated to further impair or kill marine growth on or in the vicinity of the hull.
A relatively early example is disclosed in U.S. Pat. No. 3,142,283 (Fisher) granted on Jul. 28, 1964. Fisher discloses a one-piece sheath that is first slipped around a boat hull, then secured to the boat at deck level. However, the task of xe2x80x9cslippingxe2x80x9d the sheath around the hull is labor intensive and may be easier said than done. Further, the need to secure the sheath to the boat necessarily implies the presence of suitable securing fixtures on the boat.
Another relatively early example is disclosed in U.S. Pat. No. 3,685,477 (Wood) granted on Aug. 22, 1972. Wood describes an enclosure that comprises a downwardly depending framework having a gate pivotally connected to its rear portion, the framework carrying a bag formed from a flexible sheet of waterproof material. He teaches that the framework can be attached to the sides of a boat slip or alternately to a buoyant flotation means, and that the gate may be raised or lowered with the aid of gate lines which appear to be in the nature of ropes or cables. When the gate is lowered, the boat may move into or out from the confines of the framework. When the gate is raised, the boat becomes enclosed. However, the gate lines may be awkward or inconvenient to handle and need to be secured to a dock to hold the gate in its raised position. Overall, the framework is a relatively complex structure having not only the length and width necessary to form a perimeter around the boat at water level but also a significant height extending downwardly to a depth below the bottom of the hull. In its lowered position, a portion of the gate extends to an even greater depth, thus limiting the shallowness of water in which the enclosure can be used.
A more recent example, U.S. Pat. No. 6,047,658 (Tansy) granted on Apr. 11, 2000, describes a floating enclosure dimensioned to receive a boat, the enclosure including a housing having an open top, a closed bottom, a closed forward wall, closed side walls and an open rearward wall. The side walls and forward wall all have a significant vertical dimension that (as in the case of Wood""s framework) exceeds the depth of the boat""s hull in the water. A buoyant member or members are secured to the housing to maintain the enclosure afloat. In addition, Tansy describes a gate, itself in the nature of a wall, which is pivotally connected to the bottom of the rearward wall of the housing, and which can be pivoted downwardly to allow the boat to move into or out from the confines of the housing. The gate includes a hollow buoyant portion that extends along the top of the gate, but whatever buoyancy that portion may provide appears to be deliberately defeated by a concrete weighting rod extending within the hollow portion. The hollow portion also includes a series of holes to permit water to flood or be expelled from within the hollow portion. To raise the gate from an open position to a closed position, the hollow portion is filled through a tube with air from a compressor. To secure the gate when it is closed, Tansy provides a lock. In order to get the gate to lower, Tansy uses his compressor to suck air from the buoyant portion.
Various other protective enclosures are disclosed in the prior art. For example, see U.S. Pat. No. 4,215,644 (Jackson) granted on Aug. 5, 1980; U.S. Pat. No. 5,138,963 (Eichert) granted on Aug. 18, 1992; and U.S. Pat. No. 5,152,242 (Bradley) granted on Oct. 6, 1992.
Generally, existing designs for protective enclosures are not well adapted for ease of assembly and use. In some cases, the structures involve unnecessarily complex frameworks or housings. In the same or other cases, and apart mooring lines to a dock or the like, they require cooperating fixtures or other apparatus located on a dock (as in the case of Wood) or on a boat (as in the case of Fisher). Some designs require parts of significant size (e.g. as in the case of the walls disclosed by Tansy). The need for lines or cables to raise or lower a gate as in the case of Wood is considered undesirable. Likewise, the need for a lock to secure a gate, or for a compressor to lower a gate, as in the case of Tansy is considered undesirable. Further, it may be noted that some designs require special dock facilities or attachments in order to use the product. This is undesirable because many marinas no longer will allow any device to be secured to their dock other than by means of the dock cleats that they provide for mooring purposes.
A primary object of the present invention is to provide new and improved protective enclosure for a watercraft hull which is relatively simple yet rugged in construction, easy to use, and which does not require any walls or framework extending to a substantial depth below water level other than to permit the watercraft to enter or leave the enclosure.
A related object of the present invention is to provide as part of the enclosure a new and improved gate which can be easily lowered or raised to allow the watercraft to have access to or egress from the enclosure.
In accordance with a broad aspect of the present invention, there is provided apparatus for protecting a hull of a watercraft floating in a body of water, the apparatus comprising a waterproof shroud of flexible sheet material and a collar which is floatable in the body of water while carrying the weight of the shroud. The collar has a periphery sized to extend around the hull at a distance from the hull. The shroud is sized to extend around the periphery of the collar and below the hull while suspended from the collar.
The collar includes a buoyant forward section having opposed sides and a forward end extending therebetween, and a controllably buoyant rearward section having opposed sides and a rearward end extending therebetween. The opposed sides of the rearward section are pivotally connected to the opposed sides of the forward section for pivotal movement of the rearward section between a horizontal floating position and a sunken position. In its sunken position, the rearward section extends downwardly and rearwardly from the forward section and the watercraft can move into or out from the confines of the collar and shroud. Thus, the rearward section can be regarded as a gate. When the rearward section is in its floating position while the watercraft is contained within the periphery of the collar, then the watercraft hull is effectively isolated from water outside the shroud. This will block marine organisms outside the shroud from moving towards the hull. Further, water within the shroud can be chemically treated to impair or kill existing marine growth on or in the vicinity of the hull.
The rearward section includes an interior chamber and an opening or channel that extends from the chamber to provide a water flow path between the chamber and the surrounding body of water. Controllably, the chamber may be filled either with air from an external source of pressurized air or may be allowed to flood through the channel with water from the surrounding body of water. When the chamber is flooded, the rearward section is non-buoyant and pivots to its sunken position. When the chamber is filled with sufficient air, the rearward section becomes buoyant and pivots to its floating position.
In a preferred embodiment, the apparatus includes a valve controlled air flow line for controllably directing a flow of air from an external source of pressurized air into the chamber to expel water from the chamber through the channel, and for controllably permitting the egress of air from the chamber thereby allowing said chamber to flood through said channel with water from said body of water. As discussed below in more detail, such features enable a user to raise or lower the rearward section of the collar with particular ease.
For ease of manufacture and assembly, the forward and rearward sections of the collar preferably are made using available pipe stock and couplings. The resulting structure is both strong and rigid. To further advantage, this enables the opposed sides of the rearward section to be pivotally connected to the opposed sides of the forward section, each by a flexible bellows joint that provides suitable hinge action.
The foregoing and other features and advantages of the present invention will now be described with reference to the drawings.